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Finding the Fourth Proportional to 838.26, 1,256.76 and 427.20

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Solution

The fourth proportional to 838.26, 1,256.76 and 427.20 is: 640.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.26 : 1,256.76 = 427.20 : x
  2. Step 2: Convert to fraction form
    838.26/1,256.76 = 427.20/x
  3. Step 3: Cross multiply
    838.26x = 1,256.76 × 427.20
  4. Step 4: Simplify right side
    838.26x = 536,887.87
  5. Step 5: Solve for x
    x = 536,887.87/838.26
  6. Step 6: Final answer
    x = 640.48

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.